1. VELAGAPUDI RAMAKRISHNA SIDDHARTHA
ENGINEERING COLLEGE
ELECTRONIC SAFETY ASSITANCE FOR BLIND USING
MICROCONTROLLER AND DSP VOICE PROCESSER
PRESENTTED BY
G.LALITHA

2. ABSTRACT
The main of aim this application is to providing
assistance for the blind people against obstruction. The blind
people has to wear the equipment, the equipment transmits IR
communication code into the free space. The reflected IR
communication code received by the same microcontroller.
The reflection is take place and it’s give a voice response at the
equipment

3. INTRODUCTION
 In order to help the blind people to reach their destination
safely this equipment is designed.
 The application is designed using the microcontroller and dsp
voice processor to assist the blind people. Hence the
application is given the name “Electronic safety assistance
for blind using microcontroller and dsp voice processor”.

4. THE MAIN COMPONENTS USED IN THIS
APPLICATION
Micro-Controller MCS51 Series, 89C52
IR Transmitter
IR Receiver
Buzzer
DSP voice processor

5. BLOCK DIAGRAM
DSP Voice
DSP VOICE
PROCESSOR
Processor

6. CRITERIA FOR CHOSSING AT89C52
MICROCOMTOLLER
• The AT89C52 is a low power ,high performance cmos 8 bit
Microcontroller with 8K bytes of in-system programmable
flash memory. The device is manufatured using atmel’s high
density nonvolatile memory Technology.
• AT89C52 is a powerful microcontroller that provides a highly
flexible and Cost effective solution.

7. MICROCONTROLLER DESCRIPTION
It supports the two software selectable power saving modes
one is ideal mode and other is power down mode
32 Programmable I/O Lines.
Three 16-bit Timer/Counters.
Eight Interrupt Sources.
It has 256 bytes of internal RAM.

8. IR TRANSMITTER AND IR MODULATOR

9.  IR led is used as the IR transmitter.
 IR modulator is an astable multivibrator Generates
35KHz frequency while receiving bit0 from TDX of the
microcontroller.
 TDX pin of the microcontroller generates 35KHz IR
frequency, the frequency is emitted by the IR led with
help of driver transistor.

10. IR LED
 Infrared emitting diode is a high intensity diode, molded in a
blue transparent plastic package.
 A light-emitting diode (LED) is a semiconductor
light source.
 When a light-emitting diode is forward biased
(switched on), electrons are able to recombine with
electron holes within the device, releasing energy
in the form of photons. This effect is called electroluminescence.

11.  Infrared LEDs are also used in the remote control units of
many commercial products including televisions, DVD
players, and other domestic appliances.
 For infrared LED’s, the light output is not
visible by our eyes, but can be sensed by
a variety of electronic devices

12. IR RECEIVER CONNECTED TO
MICROCONTROLLER

13.  The receiver is having IR photo diode and IR
processing comparator Opamp.
 It has 3 pins one is connected to gnd, other is vcc,
3rd pin is data pin.
 The data received at RDX pin of the microcontroller
converts into Parallel subsequently stores in serial
buffer.

14. DSP VOICE PROCESSOR APR9301 V2
 The APR9301 device offers true single-chip solid-state storage
capability and requires no software or microcontroller support.
 It provides high-quality recording and playback with a single 20to 30-second message
 Low power consumption
 User-friendly, easy-to-use operation

15. OPERATING MODES
There are four operating modes in the
APR9301 V2 voice processor.
They are:
Record Mode (Level-Activated)
Playback Mode (Edge-Activated)
Standby Mode (/CE = "0")
Power Down Mode (/CE = "1")

16. BUZZER
• A buzzer or beeper is a signaling device, usually
electronic, typically used in automobiles,
household appliances

17. ADVANTAGES
Advantages:
• As IR transmitter and receiver are inexpensive
• Power consumption is very low
• The equipment is less in size, hence it can be easily carried

18. FUTURE SCOPE
The IR rays are not omnidirectional. They
exhibit line of sight property. Due to this reason the
person can only identify the obstruction that is straight
to him. Inorder to cover the entire region surrounding
the person the system can be developed using RFID
transmitter and can be used more effectively in future.

19. FLOWCHART

20. CONCLUSION
In this work the methodology of detecting any obstruction
is described. The application helps in providing assistance for the
blind people against the obstruction. Whenever it detects the
object, it intimates the user through voice processor and the
buzzer.

21. REFERENCES
http://www.maxim-ic.com
http://www.atmel.com
http://www.wikipedia.org
http://www.google.co.in
http://www.ehow.com
http://www.8051projects.net
http://www.keil.com